Why does Descartes think he can be sure that a God who is no deceiver exists Are his arguments convincing Descartes considers himself to be sure that there is a non-deceiving God by using two different arguments in the Meditations: the so-called trademark argument, and the famous ontological argument. Although Descartes believes that they are both capable of proving the existence of God indubitably, some consideration of the arguments suggests that they are not convincing as he considers them to be. The trademark argument appears early on in the work, in the third meditation. It is important to remember the context in which the argument is used: Descartes has removed from his acceptance anything that is doubtable, and is left with the cogito. Any argument for a non-deceiving God will necessarily have to come from within himself, as that is all he has left. The trademark argument can be summed up as two simple premises: firstly, that the idea of God exists within us, and secondly, the complexity of the idea is such that only a perfect being God could have planted it within us.

One way in which this argument can easily be disproved is if it can be shown that Descartes does not possess an idea of God. To merely say, though, that just because Descartes lacks a complete understanding of Gods infinite nature means he lacks an idea of God would not, on its own, be able to disprove this. To understand the idea of God does not require one to understand all that goes with the idea: our finite nature naturally prevents us from doing this, as is discussed later. One can have the idea of how radio works whilst still lacking an understanding of the actual details of radio waves. What, though, is unconvincing about this argument, even at this stage, is the idea of saying an infinite being exists, but its infiniteness can never be fully understood by a finite being, thus God exists and gave us all the idea of him. The use of words appears to be too arbitrary infinite, omnipotent, and omniscient all appear in the text to define the concept of God by Descartes.

These are, though, just words. Although the meanings of these words are likely to be understood, it is still the case that these abstract concepts can be applied by anyone to anything, without the slightest worry about their correct use. One can have the idea of an omnipotent and infinite being, and not believe it. The atheist is just as unable to explain what this concept actually involves as the theist.

To admit to being able to understand the concept of God appears unlikely: one can have a vague idea of His probable nature, but this will not be the same as understanding. It has been suggested by some critics that by merely negating our finitude we can have an understanding of infinity. Descartes seems to take the opposite view, and asserts that our finiteness is a negation of Gods infiniteness, because in order to recognise our own finiteness, an understanding of infinity is required. This approach, though, again seems to involve playing with words rather than actually solving the problem.

Even so, there is still the question of how this idea of God was created. It seems right to say that ideas have causes, although it would be futile to always maintain that the cause of one idea was another idea, as ultimately there has to be a cause of the idea. Only God, it is maintained, in a repetition of the classic first cause argument, could have originated this idea. It would be acceptable to presume that the idea of God was taught by one generation to the next, although this would disrupt the assertion that we all have an internal idea of God. Only Descartes assertion that no finite being could have produced an idea of an infinite being fits this argument. Descartes uses the idea of degrees of reality to explain this.

For a thing to create something else it needs at least as much reality as the thing it is creating. Thus, a finite being, having a lesser degree of reality than an infinite one, could not therefore have created it. The cause must be at least as real as the effect. This interpretation seems to imply that all the properties found in the causes are to be found in the effects, which appears to be manifestly false. For example, simple atoms combine to make complex molecules.

To argue this, though, maybe to misunderstand what the terms cause and effect mean, when used in this context. Descartes may be referring to dependence. Modes depend upon the substances they need. Likewise, the complex molecules mentioned above depend upon the existence of simple atoms, thus the former are less real than the latter. In this way, it can be argued that humanity, being finite, is dependent on an infinite being, God, for its existence. It has been suggested, though, that this would mean that God would depend upon an infinite being for existence, which would be unacceptable to a monotheist like Descartes.

This view, though, is open to the (valid) criticism that intertwined with the idea of God is his eternal nature: being infinite, he depends upon nothing save himself. Or, in other words, he has the power to choose not to exist, but never makes this move. Despite these attempts at interpretation, though, the arguments still remain unconvincing. The attempt to refer to degrees of reality merely suggests how God might exist, not whether He does or not. Moreover, to suggest that the idea of God is innate and too difficult for people to invent themselves does not remove any doubt. One can have ideas of complex, even fanciful things, but that does not suggest that they are innate.

Furthermore, when to say, I have an idea of God is not very meaningful. It merely suggests the use of a word. Admittedly, describing an infinite substance may take some time, but one cannot admit to truly understanding something unless it has been adequately defined to some extent. Thus, the trademark argument is discounted. What, then, of Descartes second proof of God, the ontological argument This proof follows an argument which can be traced back to St Anselm in the 11 th Century. Descartes form of it is one of the simplest.

Put in a rudimentary way, it can be expressed as being a perfect being, and as existence forms part of the essence of being perfect, God therefore exists. When Descartes uses the term essence, he is referring to properties of a thing which is necessarily contained in the essence of the thing. The classic example of this is a triangle: its essence is that its internal angles total 180. The triangle, though, does not contain existence as part of its essence: there may, in fact, be no triangle existing in nature. Even so, its angles will still total 180.

God, though, is considered by Descartes to be a special case. The concept of God, being infinite, contains all possible perfections, thus existence cannot be separated from this. A number of objections can be raised to this idea. Descartes himself answers one such in the text, namely that just as he can imagine a triangle without it in fact existing, surely he can imagine an existing God without Him actually existing.

Descartes responds by repeating the statement that he cannot separate existence from the essence of a supremely perfect being, thus he necessarily exists. This, though, is reminiscent of Gaunilos reply to St Anselm's version of the argument, in which he suggests that one can just as easily imagine a perfect island. It does not follow that this perfect island exists solely on the grounds that one has an idea of it. It may be the case that Descartes would reply that a perfect island is akin to the winged horse he discusses, which is merely the combination of the idea of a horse and the idea of wings.

As was discussed earlier in the paragraphs relation to the trademark argument, though, it might be argued that the idea of God is merely an extension of our personal knowledge about ourselves. Descartes would refute this, as described above, but it still remains a convincing counter-argument. The most common attack on the ontological argument is the view that it considers existence to be a predicate (a word / phrase which asserts something about a proposition [OED, 1995]). Kant was one of the first to use this criticism, and it has frequently occurred ever since.

Under this view, it is asserted that nothing is actually learnt by saying that something exists. Moreover, by saying that white sheep exist, existence is not being attributed to our concept of white sheep in the way white sheep are fluffy does. Admittedly, it might be said that white sheep do not solely reside in the imagination, thus they can be said to exist, but this is to misunderstand the argument. The concept of white sheep remains the same, whether or not they actually exist.

Likewise, the concept of God, part of which is his existence, is not actually reduced by asserting that He does not exist. That a supremely perfect being would have as his essence existence, yet there is no supremely perfect being is not contradictory. It would only be contradictory to assign two predicates to an object that conflict with each other: to say that a triangle has four sides, for instance, would be an example of this. Likewise, Moore pointed out that to say All tame tigers exist can be negated in a way which Some tame tigers exist cannot.

This also seems to suggest that the verb to exist does operate in a different manner to normal predicates. Of course, it could be argued that some tame tigers exist in fiction allows a negation of the original, but this involves using a different interpretation of the verb than the one currently used. When the verb is used in this context, it is certain that existence in reality is meant, not existence in the understanding, or in fiction, etc. Thus despite Descartes claims to have a clear and distinct idea of God, in which his essence entails his existence, the ontological argument can be said to be less than convincing. Descartes clear and distinct idea of God is just that: clear and distinct in his understanding. Although this has been already touched on above, it is worth repeating: it can be effectively argued that Descartes understanding of God does not mean He actually exists.

There may not be any winged horses, but the concept can be grasped, likewise there may not be a God, but the concept can be grasped. The ontological argument consistently appears to be defining Him into existence, even though its adherents, Descartes among them, claim that this not the case. Kenny, on the other hand, has suggested that if a distinction is drawn between what is given, and what actually exists. A discussion over the nature of a triangle is an example of the former: it does not matter whether such a triangle exists or not. No triangle may actually exist, but it still has angles totalling 180. On the other hand, to say that God is perfect may be similar, but as existence forms part of the definition of what God is, He must necessarily exist.

It is hard, though, to see how this version differs fundamentally from either the ontological argument itself, or Descartes version. Descartes considers that both of these arguments prove the existence of a non-deceiving God. The proof that God is a not malevolent is obvious to Descartes, who considers that the perfect being would not deceive him. However, it may be the case that the same arguments Descartes uses can be used to prove the existence of the Devil or the malicious demon. This, though, is beyond the scope of this essay. Either way, the proofs Descartes uses are not convincing.

One does not need to have God implant an idea of Himself into ones mind to have an idea of God. Likewise, the ontological argument, however it is phrased, ultimately defines God into existence, rather than proving it. 39 f.